Internationalization Comments on CSS3 Ruby Module

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"Because the purpose of the XHTML rp element [RUBY] is to allow pre-existing user agents to parenthesize ruby
text content, an XHTML user agent should use a styling rule for these elements that avoids rendering them such as rp {display: none}."

The rp element has to be correctly handled by XML markup also, not just XHTML, so there should be an rp value for display in
section 3.1.

Whether the rp text is displayed or not is down to whether or not the user agent supports ruby - if it does, it should
automatically hide rp elements by default.

"In order to achieve that effect, vertical-ideographic layout should be set on each individual ruby. That can
be accomplished with the following simple CSS rule: ruby.bopomofo { writing-mode: tb-rl }"

This is not sufficient. The accents in bopomofo ruby are not displayed as a unidirectional run of text. Bopomofo accents are
non-combining characters that in memory follow the sequence of bopomofo alphabetic characters spelling out a syllable. However, the second to fourth
tones are displayed in a separate vertical column to the right of the alphabetic characters, and the neutral tone marker is displayed as a dot above
the column of alphabetic characters.

Please provide a more detailed explanation and examples of expected behaviour for the value right. This is
currently not clear at all.

My understanding, from talking with Michel Suignard, is that this was intended to support the bopomofo case, which requires
special placement of ruby text characters on the right side of horizontal and vertical text.

(If this is the case, it may be better to call this value 'bopomofo', since the rules for bopomofo tone placement are very
idiosyncratic.)

Left/start, and right/end are not equivalent in right to left scripts and should not be synonymous. For example, start is
towards the beginning of the line, therefore right in RTL text. Left and right should be broken out as separate values with their own
descriptions.